IR observations of the double quasar 0957 + 561 A, B and the intervening galaxy

The properties of the remarkable double quasar 0957 + 561 were first described by Walsh et al. 1 . Recently Young et al. 2 have described CCD observations of a distant galaxy associated with the quasar pair, and have identified this galaxy as a gravitational lens forming a double image of a single quasar. We report here 1.2–2.2-µm observations of the system that support the conclusion that the twin quasars are a pair of images of a single object; the quasar has an energy distribution that is unusual. The intervening galaxy is shown to be highly luminous with a bolometric luminosity of about 2 × 10 11 L .